- 40 - On the whole, this procedure is in place on all the reactors, with rare exceptions (Fessenheim for instance only has this system for one reactor). The inspectors had a simulation of this I-LHT procedure run on certain sites; these exercises were felt to be on the whole satisfactory. However, documentary anomalies highlighted the lack of regular testing of this procedure (Civaux). 2.4.10 General evaluation of the "loss of electrical power supplies" topic With regard to the electrical power supplies, the inspectors considered the EDF sites to be on the whole satisfactory, but that improvement was possible on the following points: rigorous operating and maintenance documentation (filling out of operational documents, updating of maintenance programmes); physical condition of certain fuel oil storage equipment (piping corrosion, water infiltration); management of the fluids needed by the electricity generating sets (periodic analyses); periodic inspection of the TACs on certain sites. 1.52.5 Operational management of accident situations 2.5.1 Introduction Incident or accident operations are based on the condition-based approach (APE). The APE consists in defining operating strategies according to the identified physical state of the nuclear steam supply system, regardless of the events which led to this state. If the state degrades, a permanent diagnostic enables the ongoing procedure or sequence to be abandoned and a more appropriate one to be adopted. The APE operating documents are based on the incident or accident operating rules given in chapter VI of the general operating rules (RGE). At the time core deterioration is detected (core melt), steps described in the Severe Accident Intervention Guide (GIAG) are designed to safeguard the containment in order to minimise the consequences of the accident. Responsibility is then transferred to the emergency teams who have the Emergency Team Intervention Guide (GAEC) at their disposal. In order to deal with these accident situations, the NPPs have the backup equipment (fixed or mobile) necessary in the event of an emergency. Three types of equipment are identified according to their use: equipment specified in the complementary domain accidents safety studies and presented in the various safety cases (complementary domain equipment MDC), mobile equipment used for the accident operating procedures of chapter VI of the general operating rules (mobile safety equipment MMS) and the mobile equipment used during implementation of the on-site emergency plan (PUI) when requested by the emergency crews (PUI mobile equipment). The main objectives of the inspections on this topic were to ensure the presence and applicability of the documentation necessary for accident operations (rules, guides and operating procedures), personnel training, availability, quality of testing and maintenance performed on the equipment needed to manage an accident. 2.5.2 Incident or accident operating rules Management of the operating frame of reference covering accident operations The documents needed for operation in an accident or severe accident (AG) situation are on the whole correctly managed. The nuclear power plants at Saint-Alban, Saint-Laurent, Nogent, Tricastin and Bugey nonetheless need to improve their management of chapter VI of the general operating rules: incorporation of the local and national temporary safety instructions8 into chapter VI of the RGE and into the accident operating procedures. For its part, the Paluel NPP will need to ensure the accessibility of the severe accident (AG) documentation (GIAG), by improving the ergonomics of the control room. 8 Temporary modification designed to remedy a deviation
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